error_domains.js

server.js

//npm install express request mongodb connect-domain connect-mongodb

var request = require('request'),
    express = require('express'),
    connectDomain = require('connect-domain'),
    http = require('http');

var MongoStore = require('connect-mongodb'), 
    Db = require('mongodb').Db, 
    Server = require('mongodb').Server, 
    server_config = new Server('localhost', 27017, {auto_reconnect: true, native_parser: true}), 
    db = new Db('test', server_config, {}),
    mongoStore = new MongoStore({db: db});

var app = express();

app.configure(function(){
  //if i move this line after express.session 
  //everything works as expected.
  this.use(connectDomain());

  this.use(express.cookieParser());
  this.use(express.session({secret: 'foobar', store: mongoStore }));

  this.use(app.router);

  this.use(function(err, req, res, next){
    res.end(err.message);
  });
});

app.get('/', function(req, res, next){
  var r = request.get('http://localhost:9999');
  //at this point r.domain is null.
  
  //If i explicitly add this stream to the domain it works
  //Slightly changing connect-domain to store the domain in req, if i do 
  //req.__domain.add(r); it works
  r.pipe(res);
});

http.createServer(app).listen(3000, function(){
  console.log('listening on http://localhost:3000');
});